Liverpool have agreed a fee, thought to be around £20 million, with Sunderland for Jordan Henderson, while David N'Gog is expected to head to Wearside as part of the deal.

Henderson has been linked to the Reds as a summer transfer for some time after impressing for the Black Cats over the past two seasons. The 20-year-old also picked up his first full cap for England at the end of last year because of his standout performances for his hometown club.

The deal is believed to include N'Gog moving to the Stadium of Light, subject to the striker agreeing to terms on Wearside. Should Henderson pass a medical at Anfield on Wednesday, he will become Liverpool's third big-money signing of 2011 after the January transfer of strike pair Andy Carroll and Luis Suarez.

A Sunderland spokesperson said: "A fee has been agreed with Liverpool for Jordan Henderson and he travels to Anfield today with the club's blessing."

Wearsiders chairman Niall Quinn added his thanks to Henderson for his contribution to the club.

"Jordan is a credit to himself, his family and Sunderland's Academy and everyone here wishes him the very best for the future," he said. "I am pleased that we got the deal to a level that we felt was right for our club.

"We know the areas that need strengthening and the type of player we need in order to progress and the job of bringing those players to the club is continuing at a pace."

Henderson will become Kenny Dalglish's first signing since being named permanent manager at the club. Blackpool's Charlie Adam and Aston Villa's Stewart Downing are reported to be Liverpool's next transfer targets.

The Reds made an approach for Adam during the January transfer window, but with Blackpool having since been relegated from the Premier League, a deal is expected to be completed before Dalglish and his players return to training at Melwood in early July.

Downing has refused to extend his contract at Villa Park and last week said he was "not sure" where his future lies. He has reportedly been valued at around £10 million.

Sunderland now have the potential to go on a spending spree of their own this summer with the sale of Henderson adding to that of Darren Bent in January, filling the coffers at the club. It has been reported that manager Steve Bruce is targeting as many as three strikers with the new funds, with N'Gog now expected to fill one of those places.